Pray for me, a poor sinner! Email: thebananarepublican[at]gmail[dot]com - "Neither do I wish to be obstinate in my opinions, but if I have written anything erroneous ... I submit all to the judgment and correction of the Holy Roman Church" -- St. Thomas Aquinas.

Heretical Patriarchs of Jerusalem-St. Maximus III (333-348) started out Arian
-Juvenal (422-458) was Monophysite until 451
-Origenists were John II (386-417) and Eustochius (552-564)-Martyrius (478-486) accepted the Henoticon
-if Catholicism is false, then even more Patriarchs of Jerusalem were heretics, since they announced their loyalty to and explicit desire for communion with the Catholic Church: Lazarus (1334-1368), Abraham I (1468), James III (1492-1503?), and Mark III (1503) [DTC 8.2:1003-1004]

The "Third Rome:" Moscow vs. Kiev-Princess St. Olga of Kiev was Catholic [Nicholas Brianchaninov]
-excepting Metropolitan John II of Kiev (1080-1089), Kievan Rus' was Catholic from the time of St. Vladimir the Great's 988 conversion until 1104 (Metropolitan St. Michael I [988-992] through Nicholas [1097-1101]), which saw the elevation of Orthodox Metropolitan Nicephorus I of Kiev (1104-1121) [Fr. Joseph Schweigl; Fr. Yves Congar, O.P.]
-St. Theodosius of the Kiev Caves (†1074) and the Holy Fathers of the Kiev Caves were Catholic until at least the 12th century [Bollandists; Fr. Mauricio Gordillo, S.J.]
-after 1104 not all metropolitans of Kiev were Orthodox; Catholic Metropolitans of Kiev prior to the Council of Florence include Clement Smoliatich (1147-1154), probably John IV (1164-1166), and Peter Akerovych (also his patron St. Michael of Chernigov) (1241-1246) [Fr. John Stilting, S.J.; Fr. Gordillo]
-there is no historical certainty that the following metropolitans of Kiev were Orthodox: Nicetas (1122-1126), Michael II (1130-1145), Constantine I (1156-1159), Theodore (1161-1163), Nicephorus II (1182-1198)-even Alexander Nevsky was Catholic, at least for a while starting in 1248; his contemporary, Daniel I Romanovych of Galicia (†1264) was Catholic from 1248-1256
-Peter of Kiev (1308-1326) who resided in Moscow starting in 1325, was Catholic for quite a while (until at least 1316) but became Orthodox in 1324 at the latest [Fr. Stilting; Andrew Shipman]
-Theognostus of Kiev (1328-1353) was an anti-Palamite, and so were a considerable number of Orthodox bishops and theologians through the centuries [Fr. Martin Jugie, A.A.]
-it was solely because of Grand Duke Basil II (1425–1462) that Holy Union of Florence did not take effect in Moscow, and that probably for political reasons [Shipman; Fr. Joseph Gill, S.J.]
-except for anti-Catholic Jonah of Kiev (1503–1507), the Metropolitans of Kiev (Vilnius line) were Catholic from 1439-1521 (Isidore to Joseph Soltan), and Gregory Tsamblak (1414-1420), the rival claimant to the Orthodox Metropolitan Photius of Kiev (1408-1431), was Catholic [Fr. Stilting; DTC]
-these metropolitans were Gregory II the Bulgarian (1458-1472), Michael Drucki (1474-1480), Symeon (1481-1488), Jonah Glezna (1492-1494), St. Macarius the Hieromartyr (1495-1497), Joseph II Bolgarynovich (1498–1501), and Joseph III Soltan (1508-1521)-Metropolitans of Kiev (Vilnius line) have been Catholic from 1595 to 1805 following the Holy Union of Brest; rival Orthodox line starting with Job Boretsky in 1620

The Serbian Church went into schism starting during the reign of Stephen Uroš I (1243-1276), but Stephen Uroš II Milutin of Serbia (1282–1321) professed papal primacy in his Profession of Faith for Pope John XXII (1316-1334),{6} during the reign of Nicodemus I (1316-1324).
{6} Fr. Martin Jugie, A.A. Theologia dogmatica Christianorum orientalium ab Ecclesia Catholica dissidentium IV:373.

The Bulgarian Church-Basil I of Tarnovo (1186-1232) was Catholic since 1204, and Joachim I of Tarnovo (1232-1246) was Catholic until 1235 [M. Lacko in NCE II:680]
-Catholic archbishops of Ohrid include Athanasius I (1596-1598), Porphyrius Palaeologos (1624-1627), Abraham Mesaps (1629-1637), and Meletius I (1637-1643) [Leo Allatius, De consensu utriusque Ecclesiæ p. 1092, cited by Siméon Vailhé in DTC 2.1:1196]

The Georgian Church-the schism of the Georgian Church from the Catholic Church was not known until "between 1224 and 1240" [Cyril Toumanoff in NCE VI:155], during which the Catholicoi-Patriarchs of All Georgia were Arsenius III (1222-1225), George IV (1225-1230), and Arsenius IV Bulmaisisdze (1230–1240), who was followed by Nicholas II (1240-1280)

The Photian Schism-inconsistent conduct and doctrinal attitudes of Photius

The Second Council of Lyons (1274)-

The Council of Florence-the untenable rejection of the union by Mark of Ephesus [Fr. Gill]